1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), and more particularly, to an LCD that is capable of constantly maintaining response time of liquid crystal regardless of temperature, and a method of fabricating the same.
2. Description of the Related Art
Today, with rapid development of information technology, a flat panel display having advantages of slimness, lightweight and low power consumption is in great demand. The LCD is one such flat panel display that has superior visibility, lower power consumption and lower heat radiation when compared with a cathode ray tube (CRT) having the same screen size. For this reason, the LCD is widely used in hand-held devices, computer monitors and televisions. The LCD, along with plasma display panel (PDP) or field emission display (FED) is expected to be the next generation displays.
The LCD usually includes two substrates, each having an electrode for generating an electric field and facing each other, and a liquid crystal layer interposed therebetween. When a voltage is applied to the electrodes of the respective substrates, the LCD utilizes the electric field to control liquid crystal molecules to display images.
FIG. 1 is a schematic plan view showing an LCD according to the related art, and FIG. 2 is an enlarged cross-sectional view showing a region A of the LCD of FIG. 1. Referring to FIGS. 1 and 2, the related art LCD includes a liquid crystal panel 10, a backlight module (not shown) disposed at a lower portion of the liquid crystal panel 10 to irradiate light to the liquid crystal panel 10, and a driver 11 disposed at an outer region of the liquid crystal panel 10 to drive the liquid crystal panel 10.
The liquid crystal panel 10 includes a first substrate 15 and a second substrate 17 that are spaced apart by a predetermined interval and face each other. Also, a liquid crystal layer (not shown) is interposed between the first and second substrates 15, 17.
The first substrate 15 is provided with gate lines and data lines arranged in a matrix. A plurality of thin film transistors (TFTs) acting as switching elements are formed at intersections of the gate and the data lines. Each of the TFTs has a gate electrode connected to the gate line, a source electrode connected to the data line, and a drain electrode connected to a pixel electrode. The pixel region is defined by the TFT and the pixel electrode. Also, a common electrode line 16 is formed on the first substrate 15 to supply a predetermined common voltage.
The second substrate 17 is formed with a black matrix (BM) (not shown), a color filter layer 18 and a common electrode 19. The color filter layer 18 includes red (R), green (G) and blue (B) color filters that are arranged in sequence. The black matrix may be provided among the respective color filters in order to prevent light from being irradiated to an adjacent color filter. The common electrode 19 may be formed on the whole surface of the color filter layer 18.
The liquid crystal panel 10 is provided with a seal pattern 13, at corners of an outer region of which a conductive layer 14 is formed to connect the common electrode line 16 with the common electrode 19. Accordingly, a common voltage that is applied to the common electrode line 16 can be equally supplied to the common electrode 19 through the conductive layer 14.
The backlight module includes a lamp, a light guide plate for guiding light from the lamp to the liquid crystal panel 10, a reflective plate disposed under the light guide plate to reflect the light irradiated to a lower portion of the light guide plate, and a diffusion sheet disposed on the light guide plate to diffuse the light irradiated to the liquid crystal panel 10.
The driver 11 of FIG. 1 includes a printed circuit board (PCB) on which drive circuits are mounted to generate predetermined drive signals, and a drive integrated circuit (IC) 12 connected between the PCB and the liquid crystal panel 10 to supply the drive signals to the liquid crystal panel 10. A package method of the drive IC 12 may be classified into a chip on glass (COG), a tape carrier package (TCP), a chip on film (COF), etc. FIG. 1 is an exemplary view of the TCP.
In the LCD as constructed above, the TFTs of the liquid crystal panel 10 are turned on in response to the drive signals from the driver, and the data signals are applied to the pixel electrode, thereby forming a predetermined electric field. While variation of the liquid crystals is changed due to the electric field, an amount of light transmission is controlled to display images.
The liquid crystals may be typically used at a temperature ranging from −40° C. to 90° C. When the LCD is driven at a room temperature, the liquid crystals have no influence on the response time. However, a problem occurs when the LCD is driven at the low temperature in that the response time of the liquid crystals tend to be slow at a low temperature. Accordingly, if the LCD is driven at the low temperature, the response time of the liquid crystals is degraded, thus generating a flicker, or the like. As a result, picture quality is degraded.